Electric fuse.



T. E. MURRAY.

ELECTRIC FUSE.

APPLICATION FILED MAY 2, 1912.

Patented Aug. 20, 1912 7% s 8 woe Moz;

We 6 $31, abbozum W UNITED STATES PATENT OFFICE.

THOMAS,E. MURRAY, 01: NEW YORK, N. Y.

ELECTRIC FUSE.

Specification of Letters Patent.

Patented Aug. 20, 1912.

Application filed May 2, 1912. Serial No. 694,629.

To all whom it may concern Be it known that I, THOMAS E. MURRAY, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Improvement in Electric Fuses, of which the following is a specification.

The invention relates to electric fuses more especially intended-for use in high potential circuits.

The invention consists in a continuous fuse wire or strip in coil form wound upon and around a core of refractory insulating material with its turns separated from one another. In order to connect the fuse in circuit, I conducting plates are provided which respectively make contact with the portions of the turns on opposite faces of the core.

In the accompanying drawings-Figure 1' is a perspective view showin my fuse in place between fixedpontact p ates. ,Fig; 2 is anend elevation. Fig. 2 is a perspective view of a modified form of mg fuse, in which the contact plates are secure upon the core. Fig. 4- 'is a top view of the form shown in Fig. 3. Fi 5 is a perspective view of another modi d form, in which the core is cylindrical, and Fig. 6 is a sectional view of a fuse plug. showing the cylindrical core of Fi 5 in place therein.

Similar numbers of reference indicate like arts.

1 1s a core of refractory insulating material, such as (porcelain. 2 is a fuse strip,

which is woun around and upon said core in a plurality of separated turns. Said strip is secured to the core inany suitable way.

In operation, the fuse is inserted between contact plates 3, 4, of conducting material,

so that said plates meet the port1ons of the turns on op osite'faces of the core. Said plates may be connected in circuit in any suitable way. The faces of the core may-be grooved, as shown in Fig. 3, to receive the strip. Contact plates, as 5, 6, may be secured upon opposite faces of the core in contact with the portions of the fuse strip crossing said faces, as shown in Fig. 3. To this end I may form the core with dovetailed shoulders 7 on two opposite faces and secure said plates in place bybending their edges over the edges of said projections. Where the fuse is to be adapted to the usual cylindrical fuse plug 8, Fig. 6, I wind the strip in parallel turns upon a cylindrical core 9.

A contact plate 10 is placed in the bottom ofthe plug bearing on the terminal 11. The

fuse rests upon said plate, with the portions of the strip which extend across the lower face of the core in contact with said plate. Above and in contact with the portions of the strip which extend across the upper face of the core is a contact'bar 12, which is connected tothe usual spiral shell terminal 18 on the plug. Close contact is effected between bar 12, plate 10 and the fusestrip, by means of a wedge 14 of refractory insulating material entering suitable openings in the plug wall.

I claim:

1. A! core of refractory insulatin material, a fuse strip wound around an upon said core in a plurality of separated turns,

and plates of conducting material in contact turnsand extending across said projections,

and conducting plates on said faces in contact with said fuse strip and engaging said projections.

In testimony whereof I have aflixed my signature in presence of two witnesses.

THOMAS E. MURRAY. Witnesses:

Gsmunn T. Pom, ,MAY '1. MCGABRY. 

